Triethyl phosphite → 5-Diethylphosphonomethyl-3-methylisoxazole

Participants

Reaction Steps

5-Chloromethyl-3-methylisoxazole (1.12 g) was dissolved in triethyl phosphite (2.0 ml) and heated at reflux for 1 h. The residue was then distilled under reduced pressure to give 5-diethylphosphonomethyl-3-methylisoxazole (1.47 g, 74%); bp 122°-5° C. at 0.5 mm; νmax (film) 2980, 2930, 2910, 1605, 1440, 1420, 1390, 1255, 1160, 1060-1010, 980, 900 cm-1 ; δH (CDCl3) 1.35 (3H, t, J=7 Hz, OCH2CH3), 2.30 (3H, s, CH3 -het), 3.30 (1H, d, JH-P =24 Hz, CH2 -P), 4.10 (2H, m, OCH2CH3), 6.05 (1H, d, J=3 Hz, CH-Het); δC (CDCl3) 11.4 (C5), 16.3, 16.4 (OCH2CH3), 24.6, 26.8 (C1), 62.7, 62.8 (OCH 2 CH3), 104.1, 104.2 (C3), 160.1 (C4), 163.5, 163.6 (C2); m/e (relative intensity) 233 (M+, 18%), 192 (47), 177 (41), 136 (50), 109 (100), 97 (82), 96 (35), 81 (76), 43 (32) (Found: 233.0831. C9H16NO4P requires 233.0816).

Provenance & Evidence